Now that the crazy is nearly two years in the past, the ex-"Two and a Half Men" star is actually ashamed of his behavior. (Well, some of it, anyway.) When David Letterman asked last night if Sheen ever feels embarrassed when he thinks back on the spring of 2011, the actor answered the question quickly and matter-of-factly: "Of course. Have you seen some of those interviews? That stuff's out there forever, man."

That said, Sheen still seems proud of his very public crackup's sheer audacity. "I booked a 21 city tour in 33 days with no act!" he crowed at one point during the Letterman interview, sounding equally incredulous and boastful. He also didn't miss a chance to take a swipe at his old sitcom, even as he revealed that he'd like to return to the show for its last episode: "I am dead," Sheen said, referring to the convenient subway accident that killed off his character at the beginning of season 9, "but so's the show." How's that for a violent torpedo of truth?

As funny as Sheen's quip is, it's not entirely accurate — CBS entertainment president Nina Tassler told TV critics last week that the network wants to bring Men back for an 11th season next fall, though a renewal has not yet been finalized. (Cast member Angus T. Jones is expected to stick with the show as well, even though he loosed his own Sheen-ian Men slam last fall.)

And despite Sheen's wishes, it seems unlikely that Men creator Chuck Lorre — the man Sheen once called a "sad silly fool," an "a-hole p---y loser" and a "low rent, nutless sociopath" — would welcome his ex-star back into the fold. After all, the ghost of Charlie Harper has already appeared on "Two and a Half Men;" he was simply played by Kathy Bates instead of Sheen.